1. Field of the Invention
The invention relates generally to chondroitin sulfate and chondroitin sulfate binding proteins. Methods for identifying chondroitin sulfate binding proteins and methods for identifying compounds that modulate the activity of chondroitin sulfate binding proteins are provided, as are methods of using such proteins and compounds.
2. Description of the Related Art
Glycosaminoglycans have an inherent capacity to encode functional information that rivals DNA, RNA and proteins. Specifically, these polysaccharides display diverse patterns of sulfation that are tightly regulated in vivo. Kitagawa, H. et al., J. Biol. Chem. 272, 31377-31381 (1997). Plaas, A. H. K. et al., J. Biol. Chem. 273, 12642-12649 (1998). Chondroitin sulfate (CS) glycosaminoglycans play important roles in biological processes such as neural development, viral invasion, cancer metastasis and spinal cord injury. The three major sulfation motifs found in vivo CS-A, CS-C and CS-E, differ only subtly in their sulfation pattern and are identical in terms of stereochemistry and sugar composition. The diverse sulfation patterns of CS polysaccharides have been postulated to function as molecular recognition motifs for growth factors, chemokines and other proteins. However, until now, no method existed to rapidly identify CS-binding proteins or specific sulfation motifs involved in protein recognition.